A luscious-looking olive, ripe off the sun-warmed tree, is horrible.

The substance that renders it essentially inedible is oleuropein, a phenolic compound bitter enough to shrivel your teeth. The bitterness is a protective mechanism for olives, useful for fending off invasive microorganisms and seed-crunching mammals. In the wild, olives are dispersed by birds, who avoid the bitterness issue by swallowing them whole.

Given the awfulness of the au naturel olive, you can’t help but wonder why early humans, after the first appalling bite, didn’t shun the olive tree forever.

The answer, of course, is olive oil. The olive is a drupe or stone fruit, like cherries, peaches, and plums, in which a fleshy outer covering surrounds a pit or stone, which